Pumps and compressors



6, 1958 A. DE LAAGE DE MEUX 2,833,226

PUMPS AND COMPRESSORS 2 Sheets-Sheet 1 Filed Jan. 19. 1954 Agaw DE LAAGE. EMEUX y 6, 1958 A. DE LAAGE DE MEUX ,2

PUMPS AND COMPRESSORS Filed Jan. 19. 1954 2 Sheets-Shet 2 AL.81N DE. LAAC;E Ce, Maux United States atet PUMPS AND COMPRESSORS Albn de Laage de Meux,-Montal, Quebec, Canada Application January 19, 1954, Seral No. 405,005

Claims priority, application Canada January 5, 1954 Claims. (Cl. 103-166) This invention relates to pumps and compressors and in particular to a pump and compressor embodying a novel piston arrangement.

Conventiorial pumps of the riprocating piston type which are in common use today sufier from the disad vantages of a somewhat complicated valve structure, and its attendant springs, rods, cams and geaxs. It will be evident that valveless pumps ofier valuable advantages when consideration is given to the commercial success which has been achieved by the rotary or impeller type pump. This pump however is a relatively low pressure pump and its use is restricted.

It is an object of the present invention to provide a pump of the reciprocating piston type that does not make use of valves of the conventiomal type which involve cam shafts, valve rods and springs.

It is also an object et the present invention to provide such a pump or compressor which is capable of exerting high pressures.

It is a further object '0f theinvenion to provide a pump which is capable of pumping liquids containing a percentage of non-liquid matter such as wood fibres or paper pulp.

Briefiy the invention contemplates the provision of a cylinder With a crankshaft rotatably mounted opposite one end thereof and which has two'sets of cranks thereon extending at approximately 90 from one another from the axis of rotation. The cylinder has reciprocating within it, a main piston and a secondary piston which are connected to the,crankshatt by connecting rods. A port is provided in the cylinder wall which communicates with the space between the pistons and which is positioned so as to be opened and closed by the main piston. Through the main piston, from its bottom face to its side face is a passage which is adapted to register at times with a second port in the cylinder wall.

An embodiment of the invention will now be described in detail with reference to the accompanying drawings in which Figure 1 is a side elevation in cross-section of the pump.

Figure 2 is a side eievation in cross-section of the pump at a later stage of crankshaft revolution.

Figure 3 is a side elevation in crosssection of the pump at a third stage of crankshaft revoluion.

Figure 4 is a side elevation in cross-section of the pump at a 4th stage of crankshaft revolution.

Figure 5 is a side elevation in cross-section of the pump taken at 90 to the section in Figure 1.

Figure 6 is a perspective view of the crankshatt.

Referring to Figure l it will be seen that a cylinder 10 is provided having two ports 11 and 12 therein communicating With limes 13 and 14 respectively. Cylinder 10 is open at one end and at the other has ports 15 communicating with the atmosphere. Opposite the open end of cylinder 10 is a crankshafit 16 having cranks 17 on throws or crank arms 18 and 19. Of these throws 19 is approximately twice as long as 18 and the two extend iee from the shaft 16 at an angle of approximately This can best be seen from Figure 6, which is a perspective view of the crankshaft 16. There are two sets of cranks 17, one mounted on throws 13 and the other on throws 19. The throws 18 are shorter than throws 19 and there are two throws 18 supporting a crank 17 on either side of each pair of throws 19 supporting their crank 17. in cylinder 10 are two pistons 20 and 21 connected to cranks 17 on throws 18 and 19' respectively. Piston 20 has a passage 22 extending from its bottom face 23 to its side face 24.

A novel method of linking the pistons .to the crankshaft is employed and is, illustrated in Figure 5. Here it will be seen that two elongated slots 26 are provided in the cylinder wall. These slots lie parallel to the lo gi tudinal aris of the cylinder and are placed so that a line passing through both slots lies parallel to the crank shaft 16. Wrist pins 27 are mounted on piston 20 and extend through slots 26. Connecting rods 28 link pins 27 to cranks 17 on throws 18 of crankshaft 16. It is to be noted that slots 26 are of a length equal to the distance of travel of piston 20. Piston 29 is itself of a length sufiicient to, at all positions of its travel, fully cover slots 26 so that no compression is lost.

Referring now to Figures 1 to 4 consecutively the pump will be described as undergoing one complete cycle of operation.

Figure 1 In Figure 1 piston 20 in cylinder 10 has passage 22 aligned With port 11 in the cylinder wall. Crank 17 on throw 18 is near the bottomdeadcenter position. Thus piston 20 is near the bottom of its stroke. Crank 17 on throw 19 is at approximately the mid point of its stroke and descending. Therefore as counter clockwise rotation of the crankshaft in Figure 1 continues piston 21 will drop a great distance compared to the movement of piston 20 which will move down slightly and then up to close port 11 With its side face 24. During this movement of pistons the passage 22 has been in communication with port 11 and the space 25 between the pistons bas enlarged thereby drawing fiuid through port 11 into the space 25. This suction or drawing of fluid into the space 25 continues until crank 17 on throw 19 is at bottom deadcenter when piston 20 will have moved up far enough for port 11 to be closed by side wall 24 of piston 24). This position is shown in Figure 2.

Figure 2 In Figure 2 crank 17 on throw 19 is at bottom-deadconter and crank 17 on throw 18 is mid-way in its ascending movement. T he bottom face 23 of piston 20 is aligned With the bottom of port 12. Further counter clockwise motion of crankshatt 16 will cause the immediate opening of port 12 due to the rise of piston 20. Since piston 21 is at bottomdeadcenter it will be slow to respond to this crank shaft movement and port 12 will be partly open before it begins to rise. As it does begin to rise, however, port 12 opens completely and the fluid in space 25 is forced out through port 12.

Figure 3 7 in Figure 3 piston 20 has risen to the top-dead-center position and has begun to fall while piston 21 is still rising. Port 12 is open and port 11 is closed and thus the fluid in space 25 is being forced out. through port 12 as the two pistons approach each other.

Figure 4 In Figure 4 the pistons are at their closest position and all the fiuid in space 25 has been expelled. Further counter clockwise rotation will cause passage 22 to register again with port 11 and the cycle will be repeated.

It will be observcd that further important and valuable features are embodied in this invention. If the crank shaft 16 has its direction of rotation reversed the direction of flow through the pump will be reversed.- Fluid will be drawn in through port 12 and expelled through port 11. Ports 11 and 12 are connected to limes or pipes 13 and l4,which lead to sources and destinations et fluid passing through the pump.

If fiuid under pressure is applied to ports 11 or 12 the device will operate as a motor and by altering the port through which the pressurized fluid is admitted, the direction cf rotation of the crankshaft will be reversed.

It is also noted that it is possible and equally practical to have the passage 22 lying in the secondary piston 21 rather than in the main piston 20. This would necessitate moving port 11 to a new position to enable it to communicate with passage 22, and also moving the port 12, since it is essential that the same piston should act to open and close both ports.

In its broadest aspect the invention consists of a pump or engine comprising a cylinder, a crankshaft arranged at one end of said cylinder, a first piston rcciprocal in said cylinder and connected to the crankshaft, a second piston reciprocal in the same cylinder and connected to the crankshatt in out of phase relationship with the first piston whereby to define a space et variable volume between the respective operative faces of said pistons, a port so situated in the cylinder wall as to be in communication -with said space only when the first piston is in the vicinity of its outer dead centre position, a passage extending through said first piston from the operative face thereof to a peripheral face thereof and asecond port so situated in the cylinder wall as to be in communication with said space through said passage only when the first piston is in the vicinity of its inner dead centre position.

Since either piston may be the first piston which controls opening and closing of both the ports, the phrases outer dead centre position and inner dead centre position" have been employed instead of the rather more commonly used termsof top dead centre position and bottom dead centre position. Ihe outer dead centre position for either piston is the position in which its motion changes direction while remote from the other piston. Thus, in the case of the piston remote' from the crank shaft, the outer dead centre position will be the top dead centre position. In the case of the piston near the crankshaft, the outer dead centre position will be the bottom dead centre position. Convcrsely, the inner dead centre position of each piston is the dead centre position when such piston s nearer to the other piston.

The crankshaft angle between the two pistons is not especially critical, as will be evident from consideration of the drawings. It need not be accurately 90, since the important consideration is clearly that one piston should be moving at substantially its maximum speed when the other piston is changing its direction of movement. Each piston is moving at substantially its maximum speed for quite a large crankshaft angle, i. e. about 25 on each side of the halfway position;

I claim:

l. A machine for use as a pump or engine comprising a cylinder, a crankshaft arrangcd at one end of said cylinder, a first piston reciprocal in said cylinder and connected to the crankshaft, asecond piston reciprocal in the same cylinder and connected to the crankshaft in out of phase relationship with the first piston whereby to define a space of variable volume between the respective operative faces of said pistons, a port so situated in the cylinder wall as to be in communication with said space only when the first piston is in the vicinity ofits outer dead centre position, a passage extending through said first piston from the operative face thereof to a peripheral face thereot, a second port 50 situated in the cylinder wll as to be in communication with said space through said passage only when the said first piston i in the vicinity of its inner dead centre position.

2. A machine as claimed in claim 1, wherein the crank shaft angle between the pistons is such that one piston is moving at substantially its maximum speed when the other piston changes its direction of movement.

3. A machine as claimed in claim 2, wherein the cran]:- shaft angle between the pistons is approximately 90.

4. A machine as claimed in claim 1, wherein the said first piston is connected toan arm ofthe crankshaft shorter than the arm to which the said second piston is connccted so that the stroke of said second piston is greater than the stroke of the first piston.

5. A machine as claimed in claim 4, wherein the ratio of the lengths of the crank arms is approximately 2:1.

References Cited in the file of this patent UNITED STATES PATENTS 2,535,308 Mansted Dec. 26, 1950 FOREIGN PATENTS 25,382 Austria Aug. 25, 1906 113,193 Australia May27, 1941 755,387 France Sept. 4, 1933 

